Process of carroting fur and the like and composition therefor



Patented Sept. 1, .1936

PROCESS OF CARROTING FUR AND THE LIKE AND COMPOSITION THEREFOR Constantine F. Fabian, Brookfleld, Conn., and

Alexander N. Sachanen, Luxemburg, Luxemburg, assignors, by mesne assignments, to The Non-Mercuric Carrot .Company,

Danbury,

Conn, a corporation of Connecticut No Drawing.

Application February 13, 1935, Serial No. 6,388

3 Claims. (01. $41) This invention relates to the treatment of fur and similar animal fibers (herein generically designated as fur), and more especially to give such fur improved felting properties, and said invention further relates to a. composition of matter adapted to be employed in such treatment.

In its natural state animal fur has inadequate felting properties and, as is well-known, preliminary to the formation of a suitable fur felt to be used in the manufacture of such articles as hats, must be subjected to a chemical treatment ordinarily termed carroting" to impart thereto the requisite felting properties. The procedure commonly adopted is to brush the carroting solution into the fur while the latter is still on the skin, the latter being then set to one side to allow the fur to dry and the fur being thereafter removed from the skin and made into felt.

The object of the present invention, among other things, is to so improve the carr'oting treatment and the carroting solution employed in such treatment that, while the fur has imparted to it the property of rapid felting and the capacity of producing a tight, strong felt, certain objection-- able features which have been inherent in processes heretofore in use are eliminated in whole or' in part as will be better understood from the following. Y

The carroting process is dependent on the action of chemical reagents which so act chemi- The process of carroting comprehends not only 7 a cleansing of the animal fibers from fats and other substances, the presence of which interferes with felting, but also chemical reactions of the 'carroting reagents on the proteids of the fibers. This reaction is understood to proceed from a hydrolyzing and an oxidizing action.

Thus, it is well known that strong acids, such as sulphuric acid, impart some carroting effect to animal fibers, but it is also known that sul-.- phuric acid and other strong acids which are noncarroting eifect alone of the s rong acids of the class indicated is very weak and insufilcient. The

carroting action is mucl'rmore effective in the.

presence of an oxidizing agent and especially in a the animal fibers.

combination with a catalyst. Accordingly, an

oxidizing action appears to be a chemical action in carroting. these .two reactions,hydrolyzing and an oxidizing action,-on the fur fibers producing the so-called, carrotingefiect.

The carroting treatment heretofore most commonly employed has been through the application to the fur of acarroting solution containing a mixture of nitric acid and mercuric nitrate. In this case the nitric acid acts simultaneously as an acid and as an oxidizing agent, producinga hydrolyzing and oxidizing reaction on the animal fibers, while the mercuric nitrate has a catalytic action on'the oxidizing process. At certain concentrationsof these two reagents felting proper: ties can usually be imparted to the fur.

This method of carroting, however, has certain material defects and objections, among which are the following. I 4

Unless carried out under carefully regulated conditions, difficult or impossible at all times to meet, the process tends to weaken the strength of the animal fibers, and furthermore to so change their structure that they lose in part their ability of fixing dye stuffs, with the result that such treated fibers tend to give off the dyes when washed.

In this process the hydrolyzing and oxidizing only at high concentrations. Under high concentrations its hydrolyzingaction becomes so effective that it is apt to attack or partially. destroy Accordingly, great care has to be exercised in controlling the strength of the solution so that, on the one hand, it will be of sufficient strength to give the fur adequate felting properties while, on the other hand, it will not be so strong as to impair the'quality of the fur.

This difilculty is increased by the fact that, after the solution has been brushed on the fur and the skins are set aside for-drying, and as the drying proceeds, the nitric acid becomes stronger and more concentrated and acquires an increasing and greatly intensified oxidizing effect. Such intensifled oxidizing effect tends to detrimentally affect the fibers unless carriedout under carefullyregulated physical drying conditions, within definitely maintained limits of temperature, humidity, etc., which conditions it is difficult or impracticable to-strictly regulate.

Another objection is that the preparation of the cation of the solution of mercury nitrate in nitric acid also involves the emission of noxious vapors of nitric acid. 1 s

A further objection lies in the fact that on treating white or light colored animal fibers by the mixture of nitric acid and mercuric nitrate the fibers change color and become yellow or red. This discoloration can be explained by the specific action of nitric acid and of mercuricnitrate on proteids; the latter turn yellow on heating with nitric acid and become red on heating with a solution of mercuric nitrate and nitric acid (Millon's 'test) The use of two oxidizing agents in a carroting solution, as, for example, nitric acid and hydrogen peroxide, tends to eliminate the discoloration of white or light colored animal fibers. In such case the hydrogen peroxide oxidizes and destroys the pigments on the fibers formed by the action of nitric acid and mercuric nitrate. The use, however, of two energetic agents, such as nitric acid and hydrogen peroxide, in the same carroting solution tends to produce inordinately-strong oxidization of the animal fibers which is difiicult to control, with the result that the strength of the fibers as well as their affinity for dye stuffs tends to be detrimentally afiected. Moreover, the use of hydrogen peroxide and nitric acid oftenproduces yellow colored fibers on the edges of the skins, the intensity of which discoloration depends upon the drying conditions, such as temperature, humidity, etc., which are again difiicult or impracticable to control. Furthermore, a carroting solution containing nitric acid and hydrogen peroxide cannot be stored and kept without losing much of its strength and effectiveness and must therefore be applied to the fur soon after its preparation.

Other carroting compositions have been suggested involving the use of oxidizing agents in an alkaline medium, as, for example, hydrogen peroxide in a sodium hydroxide solution. Treatments by such alkaline mediums, however, have been found to act destructively and detrimentally on the fibers of the fur.

Other methods of carroting have. been suggested involving the use of sulphuric acid alone or a mixture of sulphuric acid with an oxidizing agent. These methods avoid discoloration of white animal fibers but are not sufliciently effective to produce an adequate carroting eflect on the fibers unless concentration of the reagents is very high, and high concentration of such reagents as sulphuric acid or hydrogen peroxide acts detrime ally on and afiects the strength of the treated fibers. The use of high concentrated sulphuric acid solutions especially tends to destroy the animal fibers in the course-ofthe drying process as the sulphuric acid reaches stages of more intense concentration.

Through our improved carroting treatment, fur may -be adequately and satisfactorily carroted,

' avoiding in whole or in part numerous objections and defects in prior carroting processes.

We have found that fur can be easily and satisfactorily carroted without the use of nitric acid or mercuric nitrate but through the use of a solution containing a non-oxidizing mercury salt (in which anion N03 is absent) to serve as the catalyzing agent together with a hydrolyzing and nonreagents.

oxidizing acid and a suitable substantially nonhydrolyzing oxidizing agent.

In this carroting treatment, neither the mercury salt nor the acid has any sensible oxidizing efiect so that the oxidizing and the hydrolyzing actions are separated and effected by diflerent Accordingly, both the oxidizing and the hydrolyzing action of the carroting solution can be precisely regulated by the concentration of the oxidizing agent, the concentration of the mercury salt as a catalyst on the oxidization and the concentration of the acid as ahydrolyzing agent.

The catalytic action of mercury in carroting fur appears to be superior to that of other known catalysts and to have the property of giving to the felt a high quality of smoothness and softness of feel. We have found, however, that similar catalytic properties are provided by soluble mercury salts other than those containing the anion N03.

We have found that the required catalytic effect is obtained not only from such salts as mercuric sulphate, mercuric chloride, etc., which give the same ions as mercuric nitrate, but also from complex mercury salts, such as mercuric ammonium chloride or double salt of mercuric chloride and potassium chloride (KzHgCh), or similar salts, which give complex ions HgNHz or HgCl4, etc. f

The employment of certain complex mercury salts as catalysts in carroting compositions is desirable since such salts as a rule are less harmful as contrasted with salts which give a two valent ion of mercury and may be used in preparation of the solution and in its application to the fur without much of the danger to healthwhich has accompanied the use of mercuric nitrate.

.As examples of non-oxidizing mercury salts, accordingly, we may use in practice such salts as mercuric sulphate, mercuric chloride, mercuric ammonium chloride, double salt of mercuric chloride and potassium chloride. The composition need not be confined to a single salt but mixtures of two ormore mercury salts of the class indicated may be employed.

under normal conditions, do not have an oxidizing eifect. 'Hydrochlorlc acid not containing any oxygen has no oxidizing action. Sulphuric acid and phosphoric acid are formed of high oxygen compounds of sulphur and phosphorus which,

are among the most stable of the different compounds of these elements. For this reason these acids do not give any oxidization. Nitric acid, on the'contrary, is formed of a very unstable, high compound of oxygen which readily decomposes into lower oxygen tion of oxygen and effect.

Instead of the more expensive phosphoric acid (pure acid 85%), the mixture of sulphuric acid or hydrochloric acid with binatriumphosphate (or other soluble salt of the same acid) can be used as this mixture gives relatively inexpensive compounds with the liberawith corresponding oxidizing phosphoric acid according to the following equa- Or the solution of phosphoric acid can be obmersion or otherwise.

' equation:

Calcium sulphate formed in this reaction can be easily removed by filtration.

Sulphuric acid has a stronger hydrolyzing action than hydrochloric acid which is evidently the result of its non-volatility and therefore has a more prolonged and increasingly pronounced action upon the animal fibers during the drying stage. Accordingly we employ sulphuric acid in lower concentrations than hydrochloric acids.

0n the other hand, non-volatile but relatively weak phosphoric acid can be used in greater concentrations in carroting solutions.

The use of different acids permits treatment of the fur at diiferent values of pH and at different volatile properties of the acids employed. The most favorable chemical conditions may be chosen, depending on the individual properties of the animal fibers to be treated. Mixtures of the various acids may also be employed to advantage. For example, a mixture of volatile hydrochloric acid and non-volatile sulphuric or phosphoric acid ,may be employed to good effect. The hydrolyzing effect of such a mixture is strong in the initial steps of carrotin-g when and immediately after the solution is applied to the fur but diminish-es rapidly at the drying stage due to the evaporation 01' the hydrochloric acid. The amount of sulphuric acid (or phosphoric acid) in such a mixture remaining on the fibers may be so chosen as to be insuincient to act detrimentally on the fibers and, on the contrary, to act favorably during the subsequent felting operation. Such a mixture avoids the possible ill eiiects of the sulphuric acid alone in cases where the carroted skins are to be held in storage for a substantial period of time before being put to use.

Besides inorganic acids, use may be made of organic acids which are soluble in water and are capable of producing non-oxidizing. hydrolyzing effects. Among such organic acids in common use and relatively inexpensive are formic, oxalic,

and various chloroacetic and sulphonic acids. In the use of such organic acids it is sometimes advisable to mix the organic acid with one or more of the inorganic acids of the class previously mentioned in order to facilitatethe solubility of the mercury salts.

As oxidizing agents we may employ such substantially non-hydrolyzing substances as chlorates, persulphates, inorganic and organic'peroxides, etc.

The application of the carroting solution to the animal fibers may be carried out in the usual manner, which comprises brushing the solution into the fur while the latter is still on the skin. It may, however, be applied to the fur.by spraying it on the fur while still on the skin or the fur itself, after having been cut from the skin, may have the carrcting solution applied by im- In the latter case the concentrations of the reagents should be materially reduced ascompared tonthe concentrations used when the solution is applied by brushingor spraying on the fur while still on the skin.

- The invention will be better understood by the following specific illustrated examples of various carroting solutions which may be prepared 'actended each for application to the animal fibers while still on the skins. e

I In each of the following examples the carroting composition comprises an aqueous solution having 100 parts by weight of water together with the chemical reagents named, in the proportions named. which proportions are also given in parts by weight.

In general, the proportions of mercury salts should comprise from one to eight parts by weight, those of the inorganic acids from one to twelve parts by weight, depending on their hydrolyzing strength and those of the organic acids, which as a class have a lesser hydrolyzing strength, .irom one to twenty-five parts by weight.

The use of the described treatment not only Example 1 Parts Mercuric chloride 3 Sulphuric acid 3 Potassium chlorate' 5 Examplez Parts Mercuric sulphate 3 Hydrochloric acid 9 Natrium peroxide 4 Example 3 Parts Mercuric ammonium chloride"; 4 Hydrochloric acid 4 Sodium persulphate 5 Example 4 Parts Double salt KzI-IgCh 4 Hydrochloric acid 5 Acetylperoxide 5 Eiample 5 I Parts Mercuric ammonium chloride 5 Phosphoric acid 8 Sodium persulphate 6 Example 6 Parts Mercuric ammonium chloride 5 Sulphuric acid 8 Sodium biphosphate a 12 Hydrogen peroxide 4 Example 7 Parts Mercuric ammonium chloride 4 Phosphoric acid 6 Hydrochloric acid 2 Potassium chlorate 6 Example 8 Parts Double salt KzHgCh 4 Hydrochloric acid 3 Sulphuric acid 1 Hydrogen peroxide -4 4 Example 9 Parts Mercuric ammonium chloride 4 Hydrochloric acid 3- Formic acid ......1 5 Sodium persulphate 6 Example 10 v Parts Double salt KzI-IgCk 4 Hydrochloric acid 3 Oxalic acid 6 Potassium chlorate 8 provides a thoroughly carroted fur capable of pro ducing a fast-shrinking,tightand smooth felt, but also yields certain advantages, among which are the following:

- The solution may be easily and quickly preto be dried at high drying temperatures, thereby aooaeza shortening the time of drying and materially reducing the-time required for the carroting treatment .in its entirety,

Various changes in and departures from the ALEXANDER N. SACHANEN.

Patent No. 2,052,875.

cons'mq'rms September 1,

F. FABIAN, ET AL.

pared. Its preparation and its application may embodiments of our carroting composition may 5 be carried out without the production of noxious be made as the same have been hereinbefore exor poisonous vapors. In most of the examples emplified, all within the scope and principles of 1 previously given, the solution may be kept or our generic invention, and it is understood that i stored for a substantial period of time without the matter hereinbefore set forth is submitted as deterioration. illustrative and not in a limiting sense. 10'

The described treatment eifects no reduction in We claim: the aflinity of the animal fibers for dye stuffs but 1. The process of preparing Mr or the like for insures apermanency in the dyes. felting, which consists in subjecting the fur to The described treatment does not discolor the the'action of an aqueous carroting solution of a l5 fur fibers but leaves light colored or white carsubstantially non-hydrolyzing oxidizing agent, a

roted fur with its original, natural color unimnon-oxidizing acid capable of asubstantial hydropaired. lyzihg action on the fur, and one or more non- By proper. selection of the strength of the acid oxidizing mercuric salts soluble in water of the reagent or reagents in solution, adequate andgroup consisting of mercuric chloride, mercuric l0 thorough carroting is had without afiecting the sulphate, mercuric ammonium chloride and strength or otherwise impairing the desirable double-salts of the type KzHgCh. qualities of the animal fibers. Precautions re- 2. As a composition of matter for the carroting quired to control the carroting effect in the case of fur or the like, an aqueous carroting solution of the carroting solution produced from nitric containing a substantially non-hydrolyzing oxi- -f acid and mercuric nitrate are not required by dizing agent, a non-oxidizing acid capable of a 5 the carroting treatment by our process. The substantial hydrolyzing action on the fur, and drying of the skins and the setting of the carrot one or more non-oxidizing mercuric salts soluble may be efiected without particular regard to in water of the groupconsistlng of mercuric chlotemperatures and other drying conditions, and ride, mercuric sulphate, mercuric ammonium theskins may be stored for long periods of chloride and double salts of the type KzHgCli. 30 time without deterioration: Drying may be ef- 3. As a composition of matter for the carroting Iected under the normal factory temperatures of fur or the like, an aqueous solution containing prevailing either in winter or summer, or may an oxidizing agent, a non-oxidizing acid capable be efiected at relatively high drying temperaof asubstantial hydrolyzing action on the fur,

ture. Drying of carroted animal fibers at high and one or more non-oxidizing mercuric salts drying temperatures in the presence of strong soluble in water of the group consisting of marnon-volatile acids, such as sulphuric acid, tends curic chloride, mercuric sulphate, mercuric amto change the color and partly destroy the fibers. monium chloride and double salts of the type The-use of our composition, when employing in- KzHgCh, said solution having the proportions organic acids which are relatively volatile, such represented by 100 parts by weight of water, from as hydrochloric acid, or relatively weaker acids, 8 12025 parts by weight of said acid, and from 1 such as phosphoric acid, and also relatively weak 1 to'8 parts'by weight of said mercuric salt. stable, organic acids, such as formic, acetic 4 oxalic and chloroacetic acids, permits the fibers CONSTANTINE F. FABIAN.

It is hereby certified that error appears in the printed specification 0 the above numbered patent requiring correction as follows: Page 4, second column, line 35, claim 5, strike out ".an" and insert instead the words a substantially non-hydrolyzing; and that the said Letters Patent should be i read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 13th day of October, A. n. 1936 Henr Van arsdale Acting Commissioner-"of Patents.

ducing a fast-shrinking,tightand smooth felt, but also yields certain advantages, among which are the following:

- The solution may be easily and quickly preto be dried at high drying temperatures, thereby aooaeza shortening the time of drying and materially reducing the-time required for the carroting treatment .in its entirety,

Various changes in and departures from the ALEXANDER N. SACHANEN.

Patent No. 2,052,875.

cons'mq'rms September 1,

F. FABIAN, ET AL.

pared. Its preparation and its application may embodiments of our carroting composition may 5 be carried out without the production of noxious be made as the same have been hereinbefore exor poisonous vapors. In most of the examples emplified, all within the scope and principles of 1 previously given, the solution may be kept or our generic invention, and it is understood that i stored for a substantial period of time without the matter hereinbefore set forth is submitted as deterioration. illustrative and not in a limiting sense. 10'

The described treatment eifects no reduction in We claim: the aflinity of the animal fibers for dye stuffs but 1. The process of preparing Mr or the like for insures apermanency in the dyes. felting, which consists in subjecting the fur to The described treatment does not discolor the the'action of an aqueous carroting solution of a l5 fur fibers but leaves light colored or white carsubstantially non-hydrolyzing oxidizing agent, a

roted fur with its original, natural color unimnon-oxidizing acid capable of asubstantial hydropaired. lyzihg action on the fur, and one or more non- By proper. selection of the strength of the acid oxidizing mercuric salts soluble in water of the reagent or reagents in solution, adequate andgroup consisting of mercuric chloride, mercuric l0 thorough carroting is had without afiecting the sulphate, mercuric ammonium chloride and strength or otherwise impairing the desirable double-salts of the type KzHgCh. qualities of the animal fibers. Precautions re- 2. As a composition of matter for the carroting quired to control the carroting effect in the case of fur or the like, an aqueous carroting solution of the carroting solution produced from nitric containing a substantially non-hydrolyzing oxi- -f acid and mercuric nitrate are not required by dizing agent, a non-oxidizing acid capable of a 5 the carroting treatment by our process. The substantial hydrolyzing action on the fur, and drying of the skins and the setting of the carrot one or more non-oxidizing mercuric salts soluble may be efiected without particular regard to in water of the groupconsistlng of mercuric chlotemperatures and other drying conditions, and ride, mercuric sulphate, mercuric ammonium theskins may be stored for long periods of chloride and double salts of the type KzHgCli. 30 time without deterioration: Drying may be ef- 3. As a composition of matter for the carroting Iected under the normal factory temperatures of fur or the like, an aqueous solution containing prevailing either in winter or summer, or may an oxidizing agent, a non-oxidizing acid capable be efiected at relatively high drying temperaof asubstantial hydrolyzing action on the fur,

ture. Drying of carroted animal fibers at high and one or more non-oxidizing mercuric salts drying temperatures in the presence of strong soluble in water of the group consisting of marnon-volatile acids, such as sulphuric acid, tends curic chloride, mercuric sulphate, mercuric amto change the color and partly destroy the fibers. monium chloride and double salts of the type The-use of our composition, when employing in- KzHgCh, said solution having the proportions organic acids which are relatively volatile, such represented by 100 parts by weight of water, from as hydrochloric acid, or relatively weaker acids, 8 12025 parts by weight of said acid, and from 1 such as phosphoric acid, and also relatively weak 1 to'8 parts'by weight of said mercuric salt. stable, organic acids, such as formic, acetic 4 oxalic and chloroacetic acids, permits the fibers CONSTANTINE F. FABIAN.

It is hereby certified that error appears in the printed specification 0 the above numbered patent requiring correction as follows: Page 4, second column, line 35, claim 5, strike out ".an" and insert instead the words a substantially non-hydrolyzing; and that the said Letters Patent should be i read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 13th day of October, A. n. 1936 Henr Van arsdale Acting Commissioner-"of Patents. 

